1. Field of the Invention
The present invention relates to transmitting method and apparatus suitably adapted to a case where audio data or image data of various schemes is transmitted via an IEEE 1394 bus line, for example.
2. Description of Relevant Art
Video data, audio data, and other kinds of data are now practically transmitted among a plurality of AV devices that are interconnected through a network via an IEEE 1394 bus line. In case of the IEEE 1394 bus line, an isochronous transmission channel (Iso-channel) used in transmitting a large volume of data, such as video data and audio data, and an asynchronous transmission channel (Async-channel) used in transmitting data related to a control command or the like are available, so that more than one kind of data is transmitted.
The format used in transmitting audio data (music data) via the IEEE 1394 bus line is detailed in [Audio and Music Data Transmission Protocol] disclosed at http://www.1394TA.org.
Also, image data accompanying with the audio data can be transmitted simultaneously. For example, image data to display lyrics or still image data of an image on the jacket is occasionally transmitted simultaneously with the audio data.
Audio data may be of a kind called multi-channel audio composed of two or more channels. When the multi-channel audio is transmitted, data in each channel has to be distinguished accurately at the receiver's end. However, because the multi-channel audio has various formats, it is quite difficult to distinguish the channel structure at the receiver's end. In particular, when the audio data is transmitted via a general bus line, such as the IEEE 1394 bus line, transmission of audio data in various formats is allowed in consideration of general versatility, which makes it more difficult to distinguish the channel structure.
In addition, when the image data accompanying with the audio data is transmitted, there arises a problem that in what manner the image data should be display cannot be determined at the receiver's end unless the display pattern of the image data is specified.